I have a relative that ownes a 94 honda accord ex.I have given the car a complete tune up and i am still getting a slight hesitation when you first take off.Car doesnt have a miss and runs fine at higher rpm and doesnt do it at all when not in gear.So i was wondering if maybe it is a timing belt ,or is it someting else.i am open for any suggestions ..Thanks ..Better way to describe it is seems to kinda miss fire if you hold the brake and aplly a little gas kinda like if was outta time..i change the wires,plugs,cap and rotor,fuel filter,pcv,air filter and added injector cleaner..also was wondering if you need to clean the throttle body on those cars


Modified by AMA Racing at 4:15 AM 8/8/2005

 

When you say you gave it a "complete tune up", what exactly did you do?

 

i replaced the plugs, wires,cap,rotor,fuel filter,pvc,air filter thats pretty much it

 

Not sure if it is your problem, but did you check the coil while you were replacing the rotor and cap?

 

no i did not

 

I wouldn't think you would need to clean the throttle body but I don't see what it would hurt to clean it anyways.

The coil may not be your problem, but it doesn't take much to check. You would need a multi tester to check the resistance. I know when mine went I had horrible throttle responce whenever I would press on the gas at any speed and a little rough at idle. Then it just blew and the car cut out and wouldn't start back up.

Maybe it could be something with your fuel system. Maybe the injectors or something. Unfortunately I don't have my manual with me and I've never had to deal with a fuel problem yet, ::knocks on wood::, so I'm not familiar with what you should check on that. I'm sure someone is on here and will be able to give you some more help with that if needed.

 

any CEL? do a compression test. hopefully its not running short on any cylinders.

 

Not to be contradictive Touring, your experience is right on for your bad coil, it acted up at all speeds when you gave it the gas, when you give it the gas, you really dont give it the gas or the computer doesnt really give it the gas. Your foot on the pedal makes a request from the computer to open up the injector on time giving them more time to deliver the fuel. I have said as a fact that when you put your foot on the gas and actually move the throttle plate you are also moving the TPS, the TPS is a new version of the ole carb accellerator pump in an electrical sort of way but it too takes time to make the computer react. Having a dirty throttle body not only reduces the time of incoming air since air doesnt get in until the throttle plate gets past the dirty oily carbony build up but air getting into the engine is much more instantanious. Air getting in before the fuel is delivered is a LEAN condition, hence a hesitation. So what I just said seems to be the opposite of what I mean. If you have to open the throttle more to let air in past all the build up, you would think that this would give the fuel time to be delivered on time.

Partially the air bypass (idle circuit) is plugged but only slightly so the engine still runs ok but very near its lean limit to affect idle, letting a little more air in before fuel can be delivered is this hesitation. Remember that Honda uses a MAP sensor, it is a speed density system, open a dirty throttle plate slightly and the MAP needs to see a correct (expected as built into its programming) vacuum reading or it wont deliver the correct amount of fuel. If I am not mistaken, an engine in Closed loop (warm) let the MAP make decisions (authority) more than a TPS.

If the coil in question is ok at other speeds when the gas pedal is pressed, especially when pressed somewhat harder, then I tend to think it is good. An ohm test is ok but a scope test (amp ramp) is the best. It is well known that Honda coils have their problems but a complete tune up with throttle body cleaning and base timing and base idle adjument are a must for great results. I could be wrong, remember a cold engine needs to be richer than a hot engine so having problems cold only could mean that the coil cannot deliver enough voltag (KV) to the cold leaner cylinder, but if it wasnt lean it should fire so this is why I think that it is more lean then a weak coil in this case.

 

Yeah but if it was a low compresion cyclinder wouldnt it idle rough..the car runs great and also idles smooth..just when u first take off its like sluggish jerky feeling after that its fine...

 

What your saying makes sence. But I can't remember my 95 Accord EX having a MAP sensor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TouringAccord &raquo;</TD></TR><TR><TD CLASS="quote">What your saying makes sence. But I can't remember my 95 Accord EX having a MAP sensor.</TD></TR></TABLE>
i have the same car, its on the TB

 

oh, is it on the back side?

Having trouble remember the engine bay on that car even though I still have the motor.

 

btw what are you doing with the motor???

 

I'll PM you, don't want to get this persons thread off topic.

 

i just thought of that

sorry to the thread starter

 

OK when you started this thread you said hesitation which means lean, now you are say jerky feeling, Ok its kewl, now I am thinking coil due to the cold engine running lean and its harder to fire a colde engine when it is lean, clean the TB completely and look forward to replacing the coil if the TB doesnt fix it, let us know the outcome please.

 

what would you use to clean out the throttle body? i have the same problem and did the full tune up too.

 

carb cleaner works for me.

 

I am having this problem......

replaced distributor with no fix, cleaned EGR ports with no fix

probelem gets worse as motor heats up

 

Urban, a guy with almost 5000 posts, come on dude, start your own thread with some more specific info, what is it doing , when, what scenario, what else have you done, Y M M and all the goodies. You probably read every post on this site, have you done a search and gotten any ideas.

Motor could be heating up but not the engine coolant temp sensor, what is the voltage of the MAP sensor at idle cold or slightly warm and fully worm with the idle or off idle hesitation problem, tune up, plug wires................

 

Huh? you are joking right?

why create another post that I would delete anyway for reposting a similar topic? i constantly delete threads or combine them for being on teh same exact topic

I have looked through other threads, hence the distributor replacement, cleaning of EGR ports, Fuel pressure checks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by urbanlegend21 &raquo;</TD></TR><TR><TD CLASS="quote">why create another post that I would delete anyway for reposting a similar topic? i constantly delete threads or combine them for being on teh same exact topic</TD></TR></TABLE>



I agree, it helps to keep the forum cleaner by keeping the same related problem in one thread rather than having seperate threads for each member having a problem. That would clutter up the forum quick.


Duane_in_Japan:

You stated earlier that an Ohm test on a coil is an ok test but that a scope test is a better test. Could you elaborate more on this kind of a test. Is this something I can do myself? Why kind of tester do I need? A quick step-by-step would nice if thats not to much to ask.

Thanks

 

Glad to expand on the precedure but I am afraid it is going to take some really expensive equipment to test it properly although the prices of oscilloscopes have come down by leaps and bounds especially for the laptop, plus an amp clamp.

You need a scope and an amp clamp and you will be doing what is called non intrusive examination, its kind of like getting your prostate checked without getting the finger in the rear, but of course we know that you like the finger part LOL.

The amp clamp will be clamped around the power or ground wire to the coil and the signal on the scope is referred to as a Shark Fin Ramp, it starts at about zero volts, when the coil is started to charge it starts to draw a line on the scope going up and to the right like the leading edge of a shark fin, then at the moment the power is killed the line drops straight down like the back side of a shark fin.

If the coil has a partial internal short but still shows within specs on an ohm meter then the beginning of the leading edge will not go up and to the right as in a nice curve, it will raise straight up instantly for between a short to a longer distance, the longer the vertical rise, the more windings in the coil that are shorted.

The coil being shorted takes away from its charging ability so when the power is requested at spark time there isnt as much power to deliver, hense a weaker spark with less KVs, and less burn time and less to no coil oscillations after all the burning is done (reserve power) but all of this is seen on another trace of the oscilloscope, while you would monitor the complete spark like the hospital would monitor your heart beat. The coil may be so shorted that it cant produce a spark at all with a spark plug gap of 1.1mm NGK standard. This is another story of spark inside the cylinder and outside the cylinder with no compression being put into the formula, big difference.

Amp Ramping is one of the leading ways to diagnose many things today, not only things with coils like THE coil, injectors and relays, but anything that power goes through, remember ohms law, its a big circle, you have resistance and volts and current (amps) in everything, this just happens to be a non intrusive way of gathering info without cutting into a wire or tearing up a connector with a big fat voltmeter probe tip.

 

wow, interesting. Never knew of that test.

Thanks

 

After going to college for a year in a pretty damn good electronics program at NEI/Dunwoody, this is still the most important thing I have learned by far when it comes to troubleshooting my vehicles. Multi-meter's give you such a basic explanation of what is happening with your components, scopes ******* rock.